Scientists ID Genes that Could Lead to Tough, Disease-Resistant Varieties of Rice

Michigan Tech scientists have pinpointed genes that could be key in the development
of hardy, disease-resistant grains, including rice. Thinkstock photo

As the Earth’s human population marches toward 9 billion, the need for hardy new varieties
of grain crops has never been greater.

It won’t be enough to yield record harvests under perfect conditions. In an era of
climate change, pollution and the global spread of pathogens, these new grains must
also be able to handle stress. Now, researchers at Michigan Technological University
have identified a set of genes that could be key to the development of the next generation
of super rice.

A meta-data analysis by biologist Ramakrishna Wusirika and PhD student Rafi Shaik
has uncovered more than 1,000 genes in rice that appear to play key roles in managing
its response to two different kinds of stress: biotic, generally caused by infectious
organisms like bacteria; and abiotic, caused by environmental agents, like nutrient
deficiency, flood and salinity.

Traditionally, scientists have believed that different sets of genes regulated plants’
responses to biotic and abiotic stress. However, Wusirika and Shaik discovered that
1,377 of the approximately 3,800 genes involved in rice’s stress response played a
role in both types stress. “These are the genes we think are involved in the cross
talk between biotic and abiotic stesses,” said Wusirika.

About 70 percent of those “master” genes are co-expressive—they turn on under both
kinds of stress. Typically, the others turn on for biotic stress and turn off for
abiotic stress.

The scientists looked at the genes’ response to five abiotic stresses—drought, heavy
metal contamination, salt, cold and nutrient deprivation—and five biotic stresses—bacteria,
fungus, insect predation, weed competition and nematodes. A total of 196 genes showed
a wide range of expressions to these stresses.

Michigan Technological University is a public research university, home to more than
7,000 students from 60 countries around the world. Founded in 1885, the University
offers more than 120 undergraduate and graduate degree programs in science and technology,
engineering, forestry, business and economics, health professions, humanities, mathematics,
and social sciences. Our beautiful campus in Michigan’s Upper Peninsula overlooks
the Keweenaw Waterway and is just a few miles from Lake Superior.